Ethernet (IEEE 802.3)
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Table Of Contents
Information Model Objects (IMOs)
Link Aggregation Group Port Entry
Data Link Aggregation Container
Spanning Tree Protocol Service
Multiple Spanning Tree Protocol Service
Multiple Spanning Tree Protocol Properties
Spanning Tree Protocol Instance Information
Multiple Spanning Tree Protocol Instance Information
Per-VLAN Spanning Tree Protocol Service
Per-VLAN Spanning Tree Protocol Instance Information
Per-VLAN Spanning Tree Protocol Port Information
Rapid Spanning Tree Protocol Instance Information
Spanning Tree Protocol Port Information
Multiple Spanning Tree Protocol Port Information
VLAN Trunking Protocol Service
Vendor-Specific Inventory and IMOs
Ethernet (IEEE 802.3)
This chapter describes the level of support that Cisco ANA provides for Ethernet, as follows:
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Information Model Objects (IMOs)
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For information on network topology, see Chapter 38 "Cisco ANA VNE Topology."
Technology Description
This section provides the following Ethernet technology descriptions:
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Please see Part 1: Cisco VNEs in this guide for information about which devices support the various technologies.
Ethernet (IEEE 802.3)
Ethernet refers to the family of LAN products covered by the IEEE 802.3 standard that defines the carrier sense multiple access collision detect (CSMA/CD) protocol. Four data rates are currently defined for operation over optical fiber and twisted-pair cables: 10Base-T Ethernet (10 Mb/s), Fast Ethernet (100 Mb/s), Gigabit Ethernet (1000 Mb/s) and 10-Gigabit Ethernet (10 Gb/s).
The IEEE 802.3 standard provides MAC (Layer 2) addressing, duplexing, differential services, and flow control attributes, and various physical (Layer 1) definitions, with media, clocking, and speed attributes. It also provides a LAG (similar to EtherChannel) definition for providing both higher link capacity and availability.
VLAN (IEEE 802.1Q)
A virtual LAN (VLAN), is a logical group of hosts that communicate as if they were attached to the same network broadcast domain, even though they do not share the same physical location or network switch. Although much like a physical LAN, VLAN hosts can be grouped together even if they are not located on the same network switch. Because a VLAN is a logical entity, its creation and reconfiguration is done through software, rather than by physically locating devices.
IEEE 802.1Q, or VLAN Tagging, is an IEEE standard allowing multiple bridged networks to transparently share the same physical network link without leakage. IEEE 802.1Q (and its shortened form, dot1q) is used to refer to the encapsulation protocol used to implement this mechanism over Ethernet networks.
QinQ (IEEE802.1ad)
QinQ (IEEE802.1) tagging (also known as dot1q tunneling) is a technology that allows the nesting of an additional VLAN tag on a packet, in addition to an existing one. According to the standard, either VLAN tag is an 802.1Q header.
QinQ allows service providers to use a single VLAN to support customers who have multiple VLANs. The core service-provider network carries traffic with double-tagged, stacked VLAN (802.1Q-in-Q) headers of multiple customers while maintaining the VLAN and Layer 2 protocol configurations of each customer and without affecting the traffic of other customers.
LAG
A Link Aggregation Group (LAG) is a group of two or more network links bundled together to appear as a single link based on the IEEE 802.3ad standard. For instance, bundling two 100-Mb/s network interfaces into a single link creates one 200-Mb/s link. A LAG may include two or more network cards and two or more cables, but the software sees the link as one logical link.
A LAG provides capacity increase, load balancing, and higher link availability, which prevents the failure of any single component link leading to a disruption of the communications between the interconnected devices.
EtherChannel
EtherChannel is Cisco's link aggregation port trunking technology. Like LAG, it unifies physical Ethernet links into one link to provide high-speed links between switches, routers, and servers. An EtherChannel can be formed from two to eight active Fast Ethernet, Gigabit Ethernet, or 10 Gigabit Ethernet ports. It also provides fault tolerance in the form of from one to eight inactive failover ports, which can also be aggregated and which become active if the other active ports fail. EtherChannel is primarily a backbone network technology, providing up to 800 Mbps, 8 Gbps, or 80 Gbps of aggregate bandwidth depending on the speeds of the underlying links (100 Mbps, 1 Gbps, or 10 Gbps). Cisco's Virtual Switching System also provides Multichassis EtherChannel (MEC), in which ports can be aggregated toward different physical chassis, forming a single virtual switch.
STP
Spanning Tree Protocol (STP) is a Layer 2 link management protocol that provides path redundancy while preventing undesirable loops in the network. For a Layer 2 Ethernet network to function properly, only one active path can exist between any two devices.
STP defines a tree with a root bridge and a loop-free path from the root to all network devices in the Layer 2 network. STP forces redundant data paths into a standby (blocked) state. If a network segment in the spanning tree fails and a redundant path exists, the STP algorithm recalculates the spanning tree topology and activates the standby path.
Cisco ANA STP modeling supports devices that use the following STP variants:
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Note that Cisco ANA does not support these STP modes when they are configured along with a bridge group.
SVI
A switch virtual interface (SVI) is a VLAN of switch ports, represented by one interface to a routing or bridging system. There is no physical interface for the VLAN. The SVI provides the Layer 3 processing for packets from all switch ports associated with the VLAN.
There is one-to-one mapping between a VLAN and SVI. Only a single SVI can be mapped to a VLAN, and the SVI cannot be activated unless associated with a physical port.
SVIs simplify VLAN routing by providing default gateway for the VLAN. They also provide layer 3 switch connectivity to the switch, and provide fallback bridging when required for non routable protocols.
VTP
VLAN Trunk (or Trunking) Protocol (VTP) is a Cisco proprietary Layer 2 messaging protocol that reduces administrative chores in a switched network by managing the addition, deletion, and renaming of VLANs on a network-wide basis. It permits configuration of VLANs on a single VTP server, with the VLAN distributed through all switches in the domain. To enable this, VTP carries VLAN information to all the switches in the VTP domain, using advertisements sent over Inter-Switch Link (ISL), 802.1q, IEEE 802.10 or LAN Emulation (LANE) trunks. VTP traffic is sent over the management VLAN (VLAN1), so all VLAN trunks must be configured to pass VLAN1.
VPLS
Virtual Private LAN Services (VPLS) is a class of Layer 2 VPN that provides Ethernet-based multipoint-to-multipoint communication over MPLS networks. It allows geographically dispersed sites to share an Ethernet broadcast domain by connecting sites through pseudowires. The network then emulates the function of a LAN switch or bridge to connect the different LAN segments to create a single bridged (Ethernet) LAN.
VPLS uses the provider core to join multiple attachment circuits together to simulate a virtual bridge that connects the multiple attachment circuits together. From a customer point of view, there is no topology for VPLS. All of the CE devices appear to connect to a logical bridge emulated by the provider core. The logical bridge performs MAC address learning, just like a physical bridge.
The Virtual Switching Instance (VSI), also known as the Virtual Forwarding Instance (VFI), is the main component in the PE router which construct the logical bridge. All VSIs which construct a provider logical bridge are connected with MPLS PWs.
Learning is done based on the customer Ethernet frame arriving at the VSI. A Forwarding Information Base (FIB) keeps track of the mapping of customer Ethernet frame addressing and the appropriate pseudowire to use.
H-VPLS
Hierarchical VPLS (H-VPLS) improves the scalability characteristics of VPLS by reducing signaling overhead and packet replication requirements for the provider edge. Two types of provider edge devices are defined in this model:
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Customer edge devices connect to u-PEs directly and aggregate VPLS traffic before it reaches the n-PE, where the VPLS forwarding takes place based on the VSI. In this hierarchical model, u-PEs are expected to support Layer 2 switching and to perform normal bridging functions. Cisco VPLS uses 802.1Q Tunneling, a double 802.1Q or QinQ encapsulation, to aggregate traffic between the u-PE and n-PE. The QinQ trunk becomes an access port to a VPLS instance on an n-PE.
REP
Cisco Resilient Ethernet Protocol (REP) is a new technology implemented on Cisco Carrier Ethernet switches and intelligent service edge routers. It extends network resiliency across Cisco IP Next-Generation Network (NGN) Carrier Ethernet Design. Requiring no hardware upgrades, REP is designed to provide network and application convergence within 50 ms. In some scenarios, the network convergence times may increase to within 250 ms, but a 250-ms convergence time is still expected to have limited or no discernible effect on most network applications. REP is a segment protocol that integrates easily into existing Carrier Ethernet networks. It is not intended to replace STP, but allows network architects to limit the scope of STP domains. Since Cisco REP can also notify STP about potential topology changes, it allows for interoperability with STP. Ideally, REP can be positioned as a migration strategy from legacy spanning tree domains.
Because REP is a distributed and secure protocol, it does not rely on a master node controlling the status of the ring. Hence failures can be detected locally either through loss of signal (LOS) or loss of neighbor adjacency. Any REP port can initiate a switchover as long as it has acquired the secure key to unblock the alternate port. By default, REP elects an alternate port unless the administrator defines a preferred port. For optimal bandwidth usage and for traffic engineering, REP supports load balancing per group of VLANs.
Information Model Objects (IMOs)
This section describes the following IMOs:
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Link Aggregation Group
This object represents a LAG 802.3ad data link aggregation entity, as described in the IEEE LAG 802.3ad document. Each LAG 802.3ad data link aggregation entity will hold a ILagPortEntry for each LAG port that is a member of this aggregation group.
Link Aggregation Group Port Entry
This object describes the Link Aggregation Control configuration parameters for each aggregation port of a Link Aggregation Group.
Ethernet Interface
The data link layer Ethernet Interface object is bound by its Containing Termination Points attribute to a physical layer interface (Ethernet Physical) object. It is accessed primarily by the Virtual LAN Multiplexer/Interface, Link Aggregation Group, Cisco Ethernet Channel or IP Interface bound by its Contained Connection Termination Points attribute. It is also accessed by the Bridging Entity.
Table 18-3 Ethernet Interface (IEthernet)
MAC Address
MAC address
Product
Configuration
Duplex Mode
Duplex mode (Unknown, Full, Half)
Any
Configuration
Output Flow Control
Output flow control (Enable, Disable)
Any
Configuration
Input Flow Control
Input flow control (Enable, Disable)
Any
Configuration
IANA Type
Internet Assigned Numbers Authority (IANA) type of the sublayer
N/A
N/A
Containing Connection Termination Points
Underlying termination points (connection or physical)
Any
N/A
Contained Connection Termination Points
Bound Connection Termination Point
Any
N/A
Port Type
The port type
Any
N/A
Is ELMI Enabled
Determines whether ELMI is enabled on the interface. See Ethernet OAM for more information.
Any
Configuration
OAM Admin Status
The OAM technology administrative status (Down, Testing, Unknown, Up). See Ethernet OAM for more information.
Any
Configuration
Aggregation Group
Ethernet Aggregation technologies such as Link Aggregation (IEEE 802.1ad) and Cisco EtherChannel are used to group several physical Ethernet interfaces/links into one logical interface/link to provide higher bandwidth and availability in fault scenarios. If this Ethernet Interface participates in an aggregation group, this property specifies the OID of the aggregation group. This information is updated by the VNE model based on polling of the LAG and EtherChannel information.
Any
Configuration
Auto-Negotiate
Specify if the Ethernet port is configured to auto-negotiate with its connected peer on communication parameters such as Speed and Duplex mode. Auto-negotiation was originally defined in the FastEthernet Standard (IEEE 802.3u) and later was significantly extended in the GigabitEthernet standard (IEEE 802.3ab).
Any
Configuration
Efps
The list of EFPs (L2 sub-interfaces/service instances) which are configured on this Ethernet interface. This information is updated by the VNE model based on polling of the EFP information (L2 sub-interfaces or Service Instances).
Any
Configuration
UNI Properties
A set of User-Network-Interface properties which are available as part of the ELMI configuration of the Ethernet interface.
Any
Configuration
Ethernet Physical
The physical layer Ethernet Physical object is bound by its Containing Termination Points attribute to a Port Connector object. It is accessed by the data link layer Ethernet Interface bound by its Contained Connection Termination Points attribute.
Table 18-4 Ethernet Physical (IPhysicalLayer)
All attributes are the same as those of Physical Layer (IPhysicalLayer).
Virtual LAN Interface
The data link layer Virtual LAN Interface object, which is used in a switched LAN environment, is bound by its Containing Termination Points attribute to an Ethernet Interface object. It is accessed primarily by the network layer object (such as IP Interface) bound by its Contained Connection Termination Points attribute. It is also accessed by the Bridging Entity.
Table 18-5 Virtual LAN Interface (IVlanInterface)
Mode
VLAN mode (Access, Trunk, 802.1Q Tunnel)
Any
Configuration
Native VLAN Identification
VLAN identifier, used for untagged received and transmitted frames
Any
Configuration
Virtual LAN Table
Array of Virtual LAN Entries (instances of IVlanEntry) configured for this VLAN interface
Any
Configuration
VlanMappings
Array of all Virtual LAN Mappings (instances of IVlanMapping) defined for this VLAN interface
Product
Configuration
IANA Type
Internet Assigned Numbers Authority (IANA) type of the sublayer
N/A
N/A
Containing Connection Termination Points
Underlying termination points (connection or physical)
Any
N/A
Contained Connection Termination Points
Bound connection termination points
Any
N/A
Virtual LAN Entry
The Virtual LAN Entry object describes the association of a Virtual LAN Interface, which operates in Trunk mode, to one of the bridged Virtual LANs configured in the device.
Virtual LAN Multiplexer
The Virtual LAN Multiplexer object, used in a routed LAN environment, is bound by its Containing Termination Points attribute to an Ethernet Interface object. It is accessed primarily by the data link layer Virtual LAN Encapsulations bound by its Contained Connection Termination Points attribute.
Table 18-7 Virtual LAN Multiplexer (IVlanEncapMux)
IANA Type
Internet Assigned Numbers Authority (IANA) type of the sublayer
N/A
N/A
Containing Termination Points
Underlying termination points (Ethernet Interface)
Any
N/A
Contained Connection Termination Points
Bound connection termination points (Virtual LAN Encapsulations)
Any
N/A
Virtual LAN Encapsulation
The data link layer Virtual LAN Encapsulation object, used in a routed LAN environment, is bound by its Containing Termination Points attribute to a Virtual LAN Multiplexer object. It is accessed primarily by the Network layer object (such as IP Interface) bound by its Contained Connection Termination Points attribute. It is also accessed by the Bridging Entity.
Virtual LAN Mapping
The data link layer Virtual LAN Mapping object, used in a routed LAN environment, is bound by its Containing Termination Points attribute to a Virtual LAN Multiplexer object. It is accessed primarily by the Network layer object (such as IP Interface) bound by its Contained Connection Termination Points attribute. It is also accessed by the Bridging Entity.
Data Link Aggregation Container
The Data Link Aggregation Container object aggregates or contains a single type of data link aggregation, such as Link Aggregation Group or Cisco Ethernet Channel.
Table 18-10 Data Link Aggregation Container (IDataLinkAggregationContainer)
Data Link Aggregations
Array of single-type data link aggregations (Link Aggregation Group, Cisco Ethernet Channel)
Any
Configuration
Type
Aggregation type (Null, Ethernet Link Aggregator)
Any
Configuration
Spanning Tree Protocol Service
The Spanning Tree Protocol Service object is used in a switched LAN environment. It describes the Spanning Tree Protocol service. It is accessed only by the Logical Root's Services List attribute.
Table 18-11 Spanning Tree Protocol Service (IStpService)
Protocol Type
Spanning Tree Protocol type (Unknown, STP, RSTP, PVSTP, MST)
Any
Configuration
Current Maximum Age
The current used value for the maximum age of learned Spanning Tree Protocol port information (in hundredths of seconds)
Any
Configuration
Current Hello Time
The current used value for hello time messages' keepalive interval of a Spanning Tree Protocol root (in hundredths of seconds)
Any
Configuration
Current Forward Delay
The current used value for port delay in each of the listening and learning states, preceding the forwarding one (in hundredths of seconds)
Any
Configuration
Instance Information Table
Any
Configuration
UplinkFast State
Indicates whether the UplinkFast feature is enabled (true, false)
Any
Configuration
BackboneFast State
Indicates whether the BackboneFast feature is enabled (true, false)
Any
Configuration
Bridge Maximum Age
The value that all bridges should use (when this bridge is acting as the root) for the maximum age of learned Spanning Tree Protocol port information (in hundredths of seconds)
Any
Configuration
Bridge Hello Time
The value that all bridges should use (when this bridge is acting as the root) for hello time messages' keepalive interval of a Spanning Tree Protocol root (in hundredths of seconds)
Any
Configuration
Bridge Forward Delay
The current used value, and the value that all bridges should use (when this bridge is acting as the root) for port delay in each of the listening and learning states, preceding the forwarding one (in hundredths of seconds)
Any
Configuration
All additional attributes are the same as System Service (ISystemService)
Multiple Spanning Tree Protocol Service
The Multiple Spanning Tree Protocol Service object is used in a switched VLAN environment. It describes the Spanning Tree Protocol service. It is accessed only by the Logical Root's Services List attribute.
Table 18-12 Multiple Spanning Tree Protocol Service (IMstService)
Protocol Properties
Multiple Spanning Tree Protocol properties
Any
Configuration
All additional attributes are the same as Spanning Tree Protocol Service (IStpService).
Multiple Spanning Tree Protocol Properties
The Multiple Spanning Tree Protocol Properties object, used in a switched VLAN environment. It describes the Multiple Spanning Tree Protocol properties. It is accessed only by the Multiple Spanning Tree Protocol Service's Protocol Properties attribute.
Spanning Tree Protocol Instance Information
The following Rapid Spanning Tree Protocol Instance Information objects describe the instance information associated with and accessed by the Multiple Spanning Tree Protocol Service's Instance Information Table attribute.
Multiple Spanning Tree Protocol Instance Information
Table 18-15 Multiple Spanning Tree Protocol Instance Information (IMstInstanceInfo)
Instance Identification
Multiple Spanning Tree Protocol instance identifier
Any
Configuration
All additional attributes are the same as Spanning Tree Protocol Instance Information (IStpInstanceInfo)
Per-VLAN Spanning Tree Protocol Service
The Per-VLAN Spanning Tree Protocol Service object is used in a switched VLAN environment. It describes the Per-VLAN Spanning Tree Protocol service. It is accessed only by the Logical Root's Services List attribute.
Per-VLAN Spanning Tree Protocol Instance Information
Table 18-17 Per-VLAN Spanning Tree Protocol Instance Information (IPvstpInstanceInfo)
Protocol Type
Spanning tree protocol type (Unknown, STP, RSTP, PVSTP, MST)
Any
Configuration
Current and Bridge Maximum Age
The current used value, and the value that all bridges should use when this bridge is acting as the root, for the maximum age of learned Spanning Tree Protocol port information (in hundredths of seconds)
Any
Configuration
Current and Bridge Hello Time
The current used value, and the value that all bridges should use when this bridge is acting as the root, for hello time messages' keepalive interval of a Spanning Tree Protocol root (in hundredths of seconds)
Any
Configuration
Current and Bridge Forward Delay
The current used value, and the value that all bridges should use when this bridge is acting as the root, for port delay in each of the listening and learning states, preceding the forwarding one (in hundredths of seconds)
Any
Configuration
All additional attributes are the same as Spanning Tree Protocol Instance Information (IStpInstanceInfo)
Per-VLAN Spanning Tree Protocol Port Information
Rapid Spanning Tree Protocol Instance Information
Table 18-19 Rapid Spanning Tree Protocol Instance Information (IRstpInstanceInfo)
Force Version
Force version (Unknown, STP, RSTP, PVSTP, MST)
Any
Configuration
All additional attributes are the same as Spanning Tree Protocol Instance Information (IStpInstanceInfo)
Spanning Tree Protocol Port Information
The following Spanning Tree Protocol Port Information objects describe the port information associated with and accessed by the Spanning Tree Protocol Instance Information's Port Information Table attribute.
Multiple Spanning Tree Protocol Port Information
Table 18-21 Multiple Spanning Tree Protocol Port Information (IMstPortInfo)
Hello Time
Hello time messages' keepalive interval of a Spanning Tree Protocol root (in hundredths of a second)
Any
Configuration
All additional attributes are the same as Spanning Tree Protocol Port Information (IStpPortInfo)
Virtual Switching Instance
The Virtual Switching Instance object represents a Virtual Switching Instance (also known as VFI, Virtual Forwarding Instance) component of a VPLS logical bridge.
Table 18-22 Virtual Switch Interface (IVsi)
VPLS Instance Name
The unique VPLS instance name
IpCore
Configuration
VPLS VPN ID
The unique VPN ID in the MPLS core
IpCore
Configuration
discoveryMode
The VSI discovery mode (Manual, BGP, LDP, RADIUS, DNS, MSS/OSS, Unknown)
IpCore
Configuration
vsiMode
The VSI mode (point-to-point, multipoint, unknown)
IpCore
Configuration
Operational state
The operational status of the VPLS instance (up, down)
IpCore
Configuration
Administrative state
The configured administrative status of the VPLS instance (enabled, disabled)
IpCore
Configuration
Pseudowires
An array of Pseudowire Properties (IPseudowireProperties).
IpCore
System
Pseudowire Properties
The Pseudowire Properties object represents an MPLS pseudowire connecting two or more Virtual Switching Instances.
VLAN Tagged Interface
This IMO represents the VLAN layer of a L3 Ethernet sub-interface. It includes the configuration information of the sub-interface, for example, the VLAN tags Match Criteria, and the status of the sub-interface.
The VLANTaggedInterface IMO deprecates the IEEE802dot1q IMO that represents only a single VLAN tagged sub-interface.
Ethernet Flow Point
This IMO represents a L2 Ethernet sub-interface (or Service Instance) configured on an Ethernet port. It includes the configuration information of the sub-interface, such as the VLAN tags Match Criteria and VLAN manipulation definitions. It also include the status of the sub-interface.
Multiple EFPs can be configured on a single physical L2 traffic port, usually on the User-Network Interface [UNI] port. Each EFP can manipulate inbound frames in a different manner and make different forwarding decisions.
VLAN Trunking Protocol Service
The VLAN Trunking Protocol Service object represents a VTP configuration on a switch. It extends System Service.
Vendor-Specific Inventory and IMOs
Vendor-specific IMOs are implemented only for specific vendor devices. The following sections describe vendor-specific objects for this technology:
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Cisco Ethernet Channel
The Cisco Ethernet Channel data link layer object aggregates multiple Ethernet Interfaces, to which it is bound by its Containing Termination Points attribute. It is accessed primarily by the Virtual LAN Multiplexer/Interface or IP Interface bound by its Contained Connection Termination Points attribute. It is also accessed by the Bridging Entity.
Table 18-27 Cisco Ethernet Channel (IEthernetChannel)
Group Number
Group identifier of the aggregated Ethernet interfaces
Any
Configuration
Bandwidth
Accumulated bandwidth of all aggregated Ethernet interfaces, in Mb/s
Any
Configuration
Aggregation Protocol
Aggregation protocol (Manual, LACP, PAGP)
Any
Configuration
IANA Type
Internet Assigned Numbers Authority (IANA) type of the sublayer
N/A
N/A
MAC Address
MAC address of the aggregated Ethernet interfaces
Any
Configuration
Administrative Status
Administrative status of the aggregated interfaces
Any
Configuration
Operational Status
Operational status of the aggregated interfaces
Any
Configuration
Containing Connection Termination Points
Underlying termination points (Ethernet Interface)
Any
N/A
Contained Connection Termination Points
Bound connection termination points
Any
N/A
Cisco REP Service
The Cisco REP Service object represents REP protocol configured on a device.
Cisco REP Segment Information
The Cisco REP Segment Information object represents a single REP segment.
Table 18-29 Cisco REP Segment Information (IREPSegmentInfo)
segmentId
The ID of the REP segment.
IpCore
Configuration
isSegmentComplete
Indicates whether the segment is complete (that is, no port in the segment is in the "failed" state).
IpCore
Configuration
portsTable
An array of Cisco REP Port Information objects representing the ports on the device that belong to this REP segment.
IpCore
Configuration
Cisco REP Port Information
This object represents a REP port. REP ports belong to a REP segment, which in turn is displayed under REP service.
Service Alarms
The following alarms are supported for this technology:
Note that these alarms, apart from Cloud Problem, are related to the underlying physical interface (see Common Components).
Cisco ANA does not generate service alarms specific to QinQ technology. However, correlation takes this technology into account when performing flow analysis.
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